Children of Yog-Sothoth

The Children of Yog-Sothoth—previously Sons of...— are the result of Yog-Sothoth mating with a human female. The most famous of these progeny are Wilbur Whately and his twin brother from The Dunwich Horror, in which instance one was born as a mutated human while the other was a giant, invisible monstrosity.

In the RPG...

The Malleus Monstrorum gives stats for both the monstrous and humanoid Children of Yog-Sothoth. The humanoid variant has a slightly higher STR, INT, and POW than a typical human, and a much higher CON. As expected, the monstrous form has much higher stats all around (except for INT and POW which are the same). The humanoid form also has no unique attacks or armor above a regular human, as seen by the fact Wilbur was taken out by a dog. The monstrous form, however, cannot be harmed by physical weapons, is invisible, and has a blood drain maneuver that take both hit-points and CON. Seems like poor Wilbur really missed out in the ability stakes.

    The monstrous form only has one stat changed in the 7e Malleus Monstrorum, and that is DEX, which has been given a wider range. The human-seeming form on the other hand has had many changes. SIZ, DEX, and EDU have all increased, while STR and CON have the same average, but the range has been changed. 

In a video game...

Both humanoid and monstrous Sons of Yog-Sothoth would probably work well in a video game—with the latter obviously being a boss—but my only concern is with how common such entities would actually be. Sure, you could include Wilbur and his brother, but then I feel you'd have to include the actual plot of The Dunwich Horror to explain their presence, which I suppose wouldn't necessarily be a bad thing.

In a film...

There have already been a few adaptations of The Dunwich Horror, though I only recall seeing one of them myself, and even then, I don't recall how the twins were handled. It obviously wasn't great or I surely would have remembered it. I feel the ending of the story is quite cinematic, and with the group watching the action through binoculars from a distance, it would provide a different take on the stereotypical monster battle, though would also need some decent CGI to pull it off well.